Field induced phase transition in Pb(Zn1/3Nb2/3)O-3-8%PbTiO3 (PZN-8%PT) was investigated by measuring temperature dependence of the dielectric constant under the DC biasing field. It was clarified that the critical end point exists at 172 +/- 3 degrees C and 1.75 +/- 0.25 kV/cm in the temperature-field phase diagram. The entropy change at the transition point was discussed based on the Clausius-Clapeyron relation. The phase transition in PZN-8% PT was found to be very close to the second-order. (C) 2011 Elsevier B. V. All rights reserved.